This invention relates to an improved door operator assembly having a motorized roller for opening and closing elevator doors.
Elevators are used to transport passengers and cargo between lower and upper levels in a building. An elevator typically includes a car that is movable along guide rails that are mounted within a hoistway. Once the elevator reaches the desired building level, a door operator opens both the car doors and the hoistway doors.
The car doors can be either center opening doors or side-opening doors. Center opening doors operate at faster speeds, which is advantageous for commercial buildings with heavy traffic. Side-opening doors provide a larger car area to one side of the door, which is advantageous for handicapped access or for loading and unloading large objects. Some side opening doors use two-section or telescoping doors where the outer section moves at twice the speed of the inner section. This allows a larger door opening to be utilized in a smaller car.
Typically the door operators include a drive motor, linkages connecting the motor to the doors, and a control box for controlling the opening and closing speed of the doors. Some door operators have motors that drive rollers along guide rails mounted to the elevator car. These door operators are complicated and require a lot of packaging space. The operators are also expensive and difficult to maintain. Thus, it is desirable to provide a simplified door operator that is less expensive and more compact.
An elevator system includes an elevator cab having doors that are movable between open and closed positions at different floor locations. A rail is mounted to the cab and at least one roller is mounted for movement along the rail. The roller is operably connected to the doors and defines an axis of rotation. A motor assembly is mounted for movement with the roller along the rail and has an output for providing a rotational driving force to the roller. The motor rotates the roller about the axis of rotation along the rail to move the doors between open and closed positions. A controller is used to control the opening and closing speeds for the doors.
In one disclosed embodiment, the motor assembly includes at least one tree-axis torque motor having a stator supporting a winding and a rotor with an internal surface for supporting a plurality of magnets. An external surface of the rotor is formed as the roller for riding along the rail. The tree-axis torque motor generates a rotating magnetic field that is non-perpendicular to the axis of rotation. The magnetic field causes the rotor rotate with respect to the stator resulting in the roller moving along the rail.
In another disclosed embodiment, a planetary drive assembly is mounted to the motor. The planetary drive assembly has a plurality of planetary members mounted within the roller for providing a rotational input force to the roller. The output from the motor is in driving engagement with the planetary members to drive the roller along the rail.
In another disclosed embodiment, a worm gear assembly interconnects the motor and the roller. The worm gear assembly has a worm coupled to the output from the motor. The worm is in driving engagement with a worm gear formed about the circumference of the roller. The motor drives the worm, which drives the roller along the rail.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.